Cornflower Honey as a Model for Authentication of Unifloral Honey Using Classical Methods Combined with Plant-Based Marker Substances Such as Lumichrome

3α-Hydroxylup-20(29)-ene-23,28-dioic Acid as a Phytogenic Chemical Marker for Authenticating Schefflera octophylla (Lour.) Harms Monofloral Honey

The monofloral honey from Schefflera octophylla (Lour.) Harms (MH-Sco) are of high economic value due to their rarity and potential medicinal benefits. However, the limited investigations on the relationship of phytogenic components between the plant S. octophylla (P-Sco) and MH-Sco have an impact on MH-Sco authentication. Herein, the tentative phytogenic markers of MH-Sco were screened by comparing the metabolites of MH-Sco obtained by ultrahigh-performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (UHPLC-Q-TOF-MS/MS)-based untargeted metabolomics with the identified phytogenic chemicals from P-Sco. Combined with the mass and NMR spectral information, 3α-hydroxylup-20(29)-ene-23,28-dioic acid (HLEDA) was finally identified as the phytogenic marker of MH-Sco. A targeted ultrahigh-performance liquid chromatography-triple quadrupole mass spectrometry (UHPLC-QqQ-MS/MS)-based method was established and validated based on the purified monomer standard to measure HLEDA levels in honey samples. HLEDA determined in MH-Sco was with the content from 0.303 to 0.440 mg/kg, while HLEDA was absent in honey samples from other botanical origins, indicating the reliability of HLEDA as a chemical marker in MH-Sco authentication. This study provides the theoretical basis and industry guidance for honey quality control for commercial consumption.

Characteristic Components and Authenticity Evaluation of Chinese Honeys from Three Different Botanical Sources

We aimed to identify the characteristic phytochemicals of safflower, Chinese sumac, and bauhinia honeys to assess their authenticity. We discovered syringaldehyde, riboflavin, lumiflavin, lumichrome, rhusin [(1E,4E)-1,5-diphenylpenta-1,4-dien-3-one-O-cinnamoyl oxime], bitterin {4-hydroxy-4-[3-(1-hydroxyethyl) oxiran-2-yl]-3,5,5-trimethylcyclohex-2-en-1-one}, and unedone as characteristic phytochemicals of these three types of honeys. The average contents of syringaldehyde, riboflavin, lumiflavin, or lumichrome in safflower honey were 41.20, 5.24, 24.72, and 36.72 mg/kg; lumiflavin, lumichrome, and rhusin in Chinese sumac honey were 39.66, 40.55, and 2.65 mg/kg; bitterin, unedone, and lumichrome in bauhinia honey were 8.42, 26.33, and 8.68 mg/kg, respectively. To our knowledge, the simultaneous presence of riboflavin, lumichrome, and lumiflavin in honey is a novel finding responsible for the bright-yellow color of honey. Also, it is the first time that lumiflavin, rhusin, and bitterin have been reported in honey. We effectively distinguish pure honeys from adulterations, based on characteristic components and high-performance liquid chromatography fingerprints; thus, we seem to provide intrinsic markers and reliable assessment criteria to assess honey authenticity.